Commit 0e61400c authored by Alon Levy's avatar Alon Levy
Browse files

ccid-card-passthru: add atr check 



Signed-off-by: default avatarAlon Levy <alevy@redhat.com>
Reviewed-by: default avatarMarc-André Lureau <mlureau@redhat.com>
parent a26dfd95

hw/usb/ccid-card-passthru.c

+59 −0
Original line number Diff line number Diff line
@@ -138,6 +138,59 @@ static void ccid_card_vscard_handle_init( 
    ccid_card_vscard_send_init(card);

}



static int check_atr(PassthruState *card, uint8_t *data, int len)

{

    int historical_length, opt_bytes;

    int td_count = 0;

    int td;



    if (len < 2) {

        return 0;

    }

    historical_length = data[1] & 0xf;

    opt_bytes = 0;

    if (data[0] != 0x3b && data[0] != 0x3f) {

        DPRINTF(card, D_WARN, "atr's T0 is 0x%X, not in {0x3b, 0x3f}\n",

                data[0]);

        return 0;

    }

    td_count = 0;

    td = data[1] >> 4;

    while (td && td_count < 2 && opt_bytes + historical_length + 2 < len) {

        td_count++;

        if (td & 0x1) {

            opt_bytes++;

        }

        if (td & 0x2) {

            opt_bytes++;

        }

        if (td & 0x4) {

            opt_bytes++;

        }

        if (td & 0x8) {

            opt_bytes++;

            td = data[opt_bytes + 2] >> 4;

        }

    }

    if (len < 2 + historical_length + opt_bytes) {

        DPRINTF(card, D_WARN,

            "atr too short: len %d, but historical_len %d, T1 0x%X\n",

            len, historical_length, data[1]);

        return 0;

    }

    if (len > 2 + historical_length + opt_bytes) {

        DPRINTF(card, D_WARN,

            "atr too long: len %d, but hist/opt %d/%d, T1 0x%X\n",

            len, historical_length, opt_bytes, data[1]);

        /* let it through */

    }

    DPRINTF(card, D_VERBOSE,

            "atr passes check: %d total length, %d historical, %d optional\n",

            len, historical_length, opt_bytes);



    return 1;

}



static void ccid_card_vscard_handle_message(PassthruState *card,

    VSCMsgHeader *scr_msg_header)

{
@@ -152,6 +205,12 @@ static void ccid_card_vscard_handle_message(PassthruState *card, 
                                        VSC_GENERAL_ERROR);

            break;

        }

        if (!check_atr(card, data, scr_msg_header->length)) {

            error_report("ATR is inconsistent, ignoring");

            ccid_card_vscard_send_error(card, scr_msg_header->reader_id,

                                        VSC_GENERAL_ERROR);

            break;

        }

        memcpy(card->atr, data, scr_msg_header->length);

        card->atr_length = scr_msg_header->length;

        ccid_card_card_inserted(&card->base);